Annoying indexing problem

[Steve vRS]

My rear mech has developed an annoying index problem. Every gear, up and down, shifts crisply and accurately. Apart from one, the 4th from top.

It refuses to seat, the chain just jumps around. It is a new chain. 10 speed 105 by the way.

Any ideas?

Steve

[gazza285]

Misaligned hanger? They don't need to be far out to cause this sort of problem.

That or a worn cable.

[WinstonWolf]

Strip the cassette and examine the spacers and the 4th sprocket, could be muck or the cassette might not be fully tightened.

If it only started after replacing the chain chances are the cassette is worn.

[Steve vRS]

Someone else suggested worn cassette. I didn't think I used that gear disproportionatly more than the others in the middle of the stack.

Steve

[WinstonWolf]

As a rule of thumb you get through two or three chains per cassette.

[Steve vRS]

First chain but it is on a CX bike and gets ridden in mud, rain and other questionable substances!

Steve

[WinstonWolf]

Hmmm, probably worn then, I'd certainly pop the cassette off to clean/inspect it if it were me

[Usget]

WinstonWolf said:

As a rule of thumb you get through two or three chains per cassette.

MadDad gets through two or three chains per month...

[MC Bodge]

Rust/dirt on the cable inner or sleeve?

A slight kink/bend in the cable?

Edited by MC Bodge on Saturday 24th January 22:23

[MadDad]

Usget said:

WinstonWolf said:

As a rule of thumb you get through two or three chains per cassette.

MadDad gets through two or three chains per month...

I am not that bad - but I do have 6 bikes!!

I would suggest first checking the mech hanger, if it is not that then remove the cable, give each section of the housing a good clean with GT85 as well as all of the bearing points on the mech, then re-assemble. I know it's not a scientific approach but I have wasted many an evening trying to get one gear to index before finally giving up, stiripping/cleaning and re-assembling! - it usually does the trick...

[gazza285]

MadDad said:

I am not that bad - but I do have 6 bikes!!

Six bikes? That's 12 to 18 chains a month! I knew you did slightly more miles than average, but that's going some...

[louiebaby]

gazza285 said:

Misaligned hanger? They don't need to be far out to cause this sort of problem.

That or a worn cable.

I spent £20 on a hanger tool last year, cured problems in shifting on both bikes. A worthy investment.

[IroningMan]

louiebaby said:

I spent £20 on a hanger tool last year, cured problems in shifting on both bikes. A worthy investment.

I bought one a while ago to cure shifting problems following a tumble - easy to use and blissful silence.

[Steve vRS]

Would misalignment not give problems across the cassette? I just have one troublesome gear.

Steve

[MC Bodge]

Steve vRS said:

Would misalignment not give problems across the cassette? I just have one troublesome gear.

Steve

Clean and check the cable. Replace the cable outer and inner if necessary.

[neenaw]

Steve vRS said:

Would misalignment not give problems across the cassette? I just have one troublesome gear.

Steve

No.

I've found in the past that I've had shifting issues with one it two gears and it's been down to a slightly bent hanger.
The hanger tool is well worth the £20 or do that they cost, I find that I check mine whenever the bike's in bits getting any other work done.

[Steve vRS]

Well I've tried a new cassette as that was the easiest fix and there is no difference.

Cable next? Or I wonder if anyone nearby has a hanger alignment tool I can try...

Steve

[TwistingMyMelon]

My indexing was a bit shot, bike had been left for a while and had the frame re-aligned (steel) for the mech hanger by a decent shop

I just sprayed decent bike lube down the cable housing , and on all the pivot points. Normally I'm quite un liberal with lube as I don't want to attract dirt, but I sprayed loads on the cassette (wiped off excess) and did a 100 or so miles and everything is shifting really sweet.

Having said that, if I ever get any indexing problems, I just get my local shop to put a new cable on for a tenner, they are far more competent that I could every be and 9/10 this will fix it.

[Steve vRS]

This bike has internal cable routing which scares me so I've dropped it off at the LBS to sort out! It also has a dodgy TRP caliper which was just replaced but has foofed up again. Grrrr

Steve